Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and high plasma homocysteine in chronic hepatitis C (CHC) infected patients from the Northeast of Brazil

Association between Methylene-Tetrahydrofolate Reductase C677T Polymorphism and Human Immunodeficiency Virus Type 1 Infection in Morocco

Human immunodeficiency virus type 1 (HIV-1) infection varies substantially among individuals. One of the factors influencing viral infection is genetic variability. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is a genetic factor that has been correlated with different types of pathologies, including HIV-1. The MTHFR gene encodes the MTHFR enzyme, an essential factor in the folate metabolic pathway and in maintaining circulating folate and methionine at constant levels, thus preventing the homocysteine accumulation. Several studies have shown the role of folate on CD4+ T lymphocyte count among HIV-1 subjects. In this case-control study we aimed to determine the association between the MTHFR C677T polymorphism and HIV-1 infection susceptibility, AIDS development, and therapeutic outcome among Moroccans. The C677T polymorphism was genotyped by polymerase chain reaction followed by fragment length polymorphism digestion in 214 participants living with HIV-1 and 318 healthy controls. The results of the study revealed no statistically significant association between MTHFR C677T polymorphism and HIV-1 infection (P > .05). After dividing HIV-1 subjects according to their AIDS status, no significant difference was observed between C677T polymorphism and AIDS development (P > .05). Furthermore, regarding the treatment response outcome, as measured by HIV-1 RNA viral load and CD4+ T cell counts, no statistically significant association was found with MTHFR C677T polymorphism. We conclude that, in the genetic context of the Moroccan population, MTHFR C677T polymorphism does not affect HIV-1 infection susceptibility, AIDS development, or response to treatment. However, more studies should be done to investigate both genetic and nutritional aspects for more conclusive results.

Possible roles of methylenetetrahydrofolate reductase polymorphism and folate status in patients with early hepatitis C virus genotype 4

BACKGROUND AND STUDY AIMS

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. In Egypt, 92.5% of HCV infection cases reportedly involve infection with HCV genotype 4. HCV infection may induce liver steatosis directly and indirectly. Host genetic polymorphisms may also contribute to the pathogenesis of steatosis. Folate deficiency indirectly cuase liver damage. Folate status is mostly affected by MTHFR C677T polymorphism. The pathophysiology of thrombocytopenia (TCP) in HCV infection remains unclear. Thus, the present study investigated the roles and consequences of MTHFR C677T SNP and folate status in patients with early HCV genotype 4 infection and their relation with steatosis and thrombocytopenia.

PATIENTS AND METHODS

Fifty patients with the HCV genotype 4 and 50 healthy controls were enrolled in the study. All the participants underwent laboratory, demographic, and anthropomorphic examinations. Serum folate level was determined, and genomic analysis of MTHFR C677T SNP was performed.

RESULTS

No significant difference in allelic frequency of MTHFR C677T was observed between patients and controls. However, significantly lower serum folate level, hemoglobin level, and platelet count were found in patients than controls (p = 0.014, p = 0.005, and p = 0.001, respectively). The cholesterol, triglyceride, and high-density lipoprotein levels were also significantly lower in patients than controls (p < 0.001, p = 0.001, and p < 0.001, respectively), whereas the low-density lipoprotein level was significantly higher in patients (p < 0.001). Patients harboring the MTHFR CT genotype had a significantly lower serum folate level (p = 0.033) than the controls. Among the patients with HCV infection, those with the TT genotype had the highest body mass index (p = 0.003) and levels of cholesterol, triglyceride, and high-density lipoprotein (p = 0.007, p = 0.025, and p = 0.040, respectively).

CONCLUSION

MTHFR C677T SNP may contribute to the development of complications associated with early HCV genotype 4 infection, such as dyslipidemia and decreased folate levels.

Major Polymorphisms of Genes Involved in Homocysteine Metabolism in Malaria Patients in Ouagadougou, Burkina Faso

This study analyzed the four main polymorphisms of the genes in homocysteine metabolism in malaria patients. Forty-two randomly selected subjects, diagnosed positive for Plasmodium falciparum, were included. The four genotypes were detected by real-time PCR using the MTHFR 677C>T, MTHFR 1298A>C, MTR 2756A>G, and MTRR 66A>G detection kit (Sacace Biotechnologies REF: T01002-96-S). The results revealed frequencies of 90% 677CC, 10% 677CT, and 00% 677TT for MTHFR C677T; 78.6% 1298AA, 19% 1298AC, and 2.4% 1298CC for MTHFR A1298C; 61.9% 2756AA, 33.3% 2756AG, and 4.8% 2756GG for MTR A2756G; and 50% of 66AA, 45% of 66AG, and 5% of 66GG for MTRR A66G. Correlations were found between A2756G MTR genotypes and parasitaemia (P = 0.02), MTRR A66G and hemoglobin genotypes (P = 0.009), and MTHFR A1298C and sex (P = 0.01). This study demonstrated for the first time an association between the A2756G MTR alleles and Plasmodium falciparum malaria in Burkina Faso and gave an overview of the genotypic distribution of the major SNPs influencing the metabolism of homocysteine.

Host genetic variants in obesity-related nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a complex disease. The considerable variability in the natural history of the disease suggests an important role for genetic variants in the disease development and progression. There is evidence based on genome-wide association studies and/or candidate gene studies that genetic polymorphisms underlying insulin signaling, lipid metabolism, oxidative stress, fibrogenesis, and inflammation can predispose individuals to NAFLD. This review highlights some of the genetic variants in NAFLD.

Plasmatic higher levels of homocysteine in non-alcoholic fatty liver disease (NAFLD)

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease, which includes a spectrum of hepatic pathology such as simple steatosis, steatohepatitis, fibrosis and cirrhosis. The increased serum levels of homocysteine (Hcy) may be associated with hepatic fat accumulation. Genetic mutations in the folate route may only mildly impair Hcy metabolism. The aim of this study was to investigate the relation between liver steatosis with plasma homocysteine level and MTHFR C677T and A1298C polymorphisms in Brazilian patients with NAFLD.

METHODS

Thirty-five patients diagnosed with NAFLD by liver biopsy and forty-five healthy controls neither age nor sex matched were genotyped for C677T and A1298C MTHFR polymorphisms using PCR-RFLP and PCR-ASA, respectively, and Hcy was determined by HPLC. All patients were negative for markers of Wilson's, hemochromatosis and autoimmune diseases. Their daily alcohol intake was less than 100 g/week. A set of metabolic and serum lipid markers were also measured at the time of liver biopsies.

RESULTS

The plasma Hcy level was higher in NAFLD patients compared to the control group (p = 0.0341). No statistical difference for genotypes 677C/T (p = 0.110) and 1298A/C (p = 0.343) in patients with NAFLD and control subjects was observed. The genotypes distribution was in Hardy-Weinberg equilibrium (677C/T p = 0.694 and 1298 A/C p = 0.188). The group of patients and controls showed a statistically significant difference (p < 0.001) for BMI and HOMA_IR, similarly to HDL cholesterol levels (p < 0,006), AST, ALT, γGT, AP and triglycerides levels (p < 0.001). A negative correlation was observed between levels of vitamin B12 and Hcy concentration (p = 0.005).

CONCLUSION

Our results indicate that plasma Hcy was higher in NAFLD than controls. The MTHFR C677T and A1298C polymorphisms did not differ significantly between groups, despite the 677TT homozygous frequency was higher in patients (17.14%) than in controls (677TT = 4.44%) (p > 0.05). The suggested genetic susceptibility to the MTHFR C677T and A1298C should be confirmed in large population based studies.